Australia: Dog Tests Positive For Hendra Virus

 

 

 

Nipah/Hendra Virus & Fruit Bat Home Range – WHO

 

 

 

# 5716

 

 

Over the past month more than a dozen horses in and around Queensland Australia have died from the Hendra Virus – a pathogen normally carried by flying foxes (bats), but that can be transmitted to horses and, on rare occasions, to humans as well.

 

The virus was first isolated in 1994 after the deaths of 13 horses and a trainer in Hendra, a suburb of Brisbane, Australia. A stable hand, who also cared for the horses, was hospitalized, but survived.

 

Another outbreak took place in MacKay, 1000 km to the north of Brisbane, the previous month. Two horses died, and the owner was hospitalized several weeks later with meningitis. 

 

He recovered, but developed neurological symptoms and died 14 months later.

Subsequent studies have showed a high prevalence of the newly identified Hendra virus in Pteropid fruit bats (flying foxes) in the region.

 

In 1999, a very similar virus emerged at a Malaysian pig farm, resulting in 105 human deaths and the culling of one million pigs.  Exported pigs caused another outbreak at an abattoir in Singapore, resulting in 11 infections and 1 additional death.

This virus was designated Nipah, named after the place where it was first isolated in humans. It too, is believed to be carried by the fruit bat.

 

 

Since then, there have been scattered outbreaks of both viruses in Australia (Hendra virus) and in Bangladesh and adjacent parts of India (Nipah).  Of the two, the Nipah virus has infected and killed the most humans.

 

For more background on these two rare viruses, the CDC’s Special Pathogens Branch maintains a fact sheet:

 

Hendra Virus Disease and Nipah Virus Encephalitis

 

The World Health Organization maintains a website on the Hendra Virus (Hendra Virus (HeV) Infection) and Nipah Virus (Nipah Virus (NiV) Infection) on their Global Alert And Response (GAR) site.

 

Today, we’ve news of an unusual discovery out of Australia.  

 

A dog on one of the quarantined ranches in Queensland has tested positive for antibodies to the Hendra Virus.  Although the dog appears healthy, this indicates a previous exposure to the virus.

 

And this marks the first known infection of a dog by the virus in the wild.

 

The following notice appears on the Queensland Government Primary Industry & Fisheries website:

 

Current situation as at 26 July 2011

The Australian Animal Health Laboratory (AAHL) in Geelong has confirmed that a dog has tested positive for Hendra virus.

 

This is an unprecedented situation, and the first time outside a laboratory that an animal other than a flying fox or horse, or a human has been confirmed with Hendra virus infection.

 

Biosecurity Queensland´s policy is to test cats and dogs on properties where there are infected horses.

 

The remaining horses and dogs on this property are still being monitored daily and show no signs of illness.

 

We recommend that people keep dogs and cats away from sick horses to reduce the risk of such an infection happening.

 

 

While it is too soon to gauge the impact of this particular discovery, anytime a virus jumps species we tend to pay close attention.

 

Many of the common illnesses we think of as `human’ diseases actually began in other species, and only later migrated to humans.

 

Tuberculosis probably jumped to humans when man began to domesticate goats and cattle. Measles appears to have evolved from canine distemper and/or the Rinderpest virus of cattle.   And Influenza, as most of you know, is native to aquatic birds.

 

The list of zoonotic diseases (those shared between humans and animals) is long and continually expanding, and includes: SARS, Babesiosis, Borrelia (Lyme), Nipah, Hendra, Malaria, Hantavirus, Ebola, Bartonella, Leptospirosis, Q-Fever, bird flu and many, many others.

 

When a virus adapts to a new host, it not only gives it fresh opportunities to mutate and evolve, it provides another potential vector to spread the pathogen.

 

And when that host is a dog or a cat – animals with whom humans closely interact – the risks of spreading to humans are even greater.

 

As the following article from the Sydney Morning Herald tells us, in light of this latest discovery scientists are now tasked with determining what – if any – changes may have occurred in the Hendra virus.

 

 

Scientists guessing over Hendra dog

Kym Agius, Jessica Marszalek and Petrina Berry

July 26, 2011 - 5:49PM

AAP

The first dog to contract the Hendra virus has scientists guessing whether the virus is being transmitted differently or if humans can now catch the disease from canines.

(Continue . . . )

 

 

For now, there are far more questions than answers.

 

 

 

»» Read More

Korea: Interspecies Transmission of Canine H3N2

 

 

 

# 5669

 

Many of the common illnesses we think of as `human’ diseases actually began in other species, and only later migrated to humans. The age of emerging infectious diseases in humans really began in earnest about 10,000 years ago when man began to domesticate – and live in close proximity to – other animals.   

 

• The scourge of Tuberculosis, which now infects 1/3rd of humanity, probably jumped to humans when man began to coral and raise its traditional hosts; goats and cattle.
• Measles appears to have evolved from canine distemper and/or the Rinderpest virus of cattle.  
• Influenza, as most of you know, is native to aquatic birds – but jumped species thousands of years ago and many strains have adapted to humans, pigs, and other species.

 

The list of zoonotic diseases (those shared between humans and animals) is long and continually expanding, and includes: SARS, Babesiosis, Borrelia (Lyme), Nipah, Hendra, Malaria, Hantavirus, Ebola, Bartonella, Leptospirosis, Q-Fever, bird flu and many, many others.

 

Yet despite these disease overlaps, viruses generally adapt to a fairly narrow range of species. 

 

Horse viruses generally attack equines, and not say, cats and dogs.   Cat viruses tend to attack felines, and not birds.  Bird viruses usually only infect avian species.

 

The species that a virus will infect is known as its host range.  And while usually limited, it isn't always the case.

 

Rabies is a good example of a virus that can infect an extraordinarily wide range of species.

 

 

 

We know that every once in awhile, viruses will suddenly jump to a new species. A couple of recent examples include:

 

The H5N1 bird flu virus, which has been unusually promiscuous: showing up in cats (including tigers), dogs, martens, civets, and of course humans. Researchers have successfully infected cattle with the H5N1 virus, along with ferrets and mice for testing.

 

H3N8 Canine influenza, which only showed up in dogs in 2004, had been known to infect horses for the past 40 years.

 

 

All of which serves as prelude to a report that appears in the latest edition of the Journal of General Virology, that finds a recently emerged canine H3N2 influenza virus common in Korea has now adapted to infect domestic cats.

 

 

Interspecies transmission of the canine influenza H3N2 virus to domestic cats in South Korea, 2010

D.S. Song, D.J. An, H.J. Moon, M.J. Yeom, H.Y. Jung, W.S. Jung, S.J. Park, H.K. Kim, S.Y. Han, J.S. Oh, B.K. Park, J.K. Kim, H. Poo, R.G. Webster, K. Jung and B.K. Kang

Abstract

In the last 4 years, incidences of endemic or epidemic respiratory diseases associated with canine influenza H3N2 virus in Asian dogs have been reported in countries such as South Korea and China. Canine species were considered to be the new natural hosts for this virus.

However, at the beginning of 2010, influenza-like respiratory signs, such as dyspnea, were also observed among cats as well as in dogs in an animal shelter located at Seoul, South Korea. The affected cats showed 100% morbidity and 40% mortality.

We were able to isolate a virus from the lung specimen of a dead cat that had suffered from the respiratory disease, in embryonated chicken eggs. The 8 viral genes isolated were almost identical to those of the canine influenza H3N2 virus suggesting interspecies transmission of canine influenza H3N2 virus to the cat.

Moreover, 3 domestic cats infected with intranasal canine/Korea/GCVP01/07 (H3N2) all showed elevated rectal temperatures, nasal virus shedding, and severe pulmonary lesions, such as suppurative bronchopneumonia.

Our study for the first time shows that cats are susceptible to canine influenza H3N2 infection, suggesting that cats may play an intermediate host role in transmitting the H3N2 virus among feline and canine species, which could lead to the endemic establishment of the virus in companion animals.

Such a scenario raises a public health concern, as the possibility of the emergence of new recombinant feline or canine influenza viruses in companion animals with the potential to act as zoonotic infection cannot be excluded.

 

 

The canine H3N2 virus only just appeared in Korea in 2007, and unlike the canine H3N8 virus seen in the United States, appears to have jumped directly from an avian source.

 

In 2008 the CDC’s EID Journal carried the following report on this newly emerging canine flu.

 

Transmission of Avian Influenza Virus (H3N2) to Dogs

Daesub Song, Bokyu Kang, Chulseung Lee, Kwonil Jung, Gunwoo Ha, Dongseok Kang, Seongjun Park, Bongkyun Park, and Jinsik Oh

Abstract

In South Korea, where avian influenza virus subtypes H3N2, H5N1, H6N1, and H9N2 circulate or have been detected, 3 genetically similar canine influenza virus (H3N2) strains of avian origin (A/canine/Korea/01/2007, A/canine/Korea/02/2007, and A/canine/Korea/03/2007) were isolated from dogs exhibiting severe respiratory disease.

 

To determine whether the novel canine influenza virus of avian origin was transmitted among dogs, we experimentally infected beagles with this influenza virus (H3N2) isolate. The beagles shed virus through nasal excretion, seroconverted, and became ill with severe necrotizing tracheobronchitis and bronchioalveolitis with accompanying clinical signs (e.g., high fever).

Consistent with histologic observation of lung lesions, large amounts of avian influenza virus binding receptor (SAα 2,3-gal) were identified in canine tracheal, bronchial, and bronchiolar epithelial cells, which suggests potential for direct transmission of avian influenza virus (H3N2) from poultry to dogs.

Our data provide evidence that dogs may play a role in interspecies transmission and spread of influenza virus.

 

 

The good news is that so far, these new canine viruses haven’t shown the ability to infect humans. 

 

But as the author’s of the EID study above point out:

 

Transmission of avian influenza A virus to a new mammalian species is of great concern, because it potentially allows the virus to adapt to a new mammalian host, cross new species barriers, and acquire pandemic potential.

 

Companion animals, such as dogs and cats, are of particular concern because of how closely humans interact with them.

 

While pigs might be biologically better suited as a `mixing vessel’ for influenza (see The (Swine) Influenza Reassortment Puzzle), there are far more opportunities for transmission between humans and their pets.

 

In terms of their potential to spread rapidly among humans, and cause significant morbidity and mortality, few viruses can compete with influenza. As we saw in 2009, a new influenza virus can jump species and spread around the globe in a matter of months.

 

A recurring theme in this blog is that nature’s bio lab is open 24/7, and that it is constantly trying out new genetic combinations looking for an evolutionary advantage. 

 

And for a virus, jumping to a new, immunologically naive species is like hitting the jackpot; a fresh supply of hosts and an opportunity to adapt further.

 

Which is why we watch these species jumps with more than a passing interest.

»» Read More

Companion Animals And Novel H1N1

 

 

# 5315

 

 

Colorized transmission electron micrograph (TEM) of HN1 virus – Credit CDC PHIL) 

 

Unlike `normal’ strains of human-adapted seasonal influenza - which are thought to rarely (if ever) infect dogs, cats, and other companion animals - the 2009 H1N1 virus has been observed a number of times in pets over the past 18 months.

 

Given that relatively few companion animals get tested for the H1N1 virus, and the likelihood that some animals only experience mild or sub-clinical symptoms of infection, the true prevalence of H1N1 infection among household pets is unknown. 

 

Yesterday, another veterinary industry alert was issued by IDEXX Laboratories - a company that produces a veterinary influenza test kit - regarding the first known H1N1 infection of 2011 in a domestic cat.

 

First some excerpts from the press release, then I’ll be back with more on pets and influenza.

 

 

First confirmed 2011 case of H1N1 influenza virus infection reported in a domestic cat

February 14, 2011

One cat with severe respiratory disease from Wisconsin has tested positive for the H1N1 influenza virus with the IDEXX H1N1 Influenza Virus RealPCR™ Test.

 

Two cats from the same household presented to a veterinary emergency hospital in respiratory distress. The owners reported to have been suffering from the flu themselves at the time the cats developed severe respiratory signs.

 

After intensive supportive care that included ventilator support, the 6-year-old male domestic shorthair (DSH) was euthanized. The IDEXX Feline Upper Respiratory Disease (URD) RealPCR™ Panel was performed using fluid obtained at the time of intubation for ventilation and was positive for the H1N1 influenza virus. The second cat, a 10-year-old female DSH, originally responded to supportive therapy but relapsed and was euthanized 8 days after presentation.

 

An oropharyngeal swab was obtained at the time of euthanasia for testing, but it was negative for H1N1 influenza virus. Given the strong-positive quantitative real-time PCR result in the first cat, the H1N1 influenza virus is still the presumptive cause of respiratory disease in the second cat. The shedding period of influenza viruses is short, which may have been responsible for the negative PCR result.

(Continue . . .)

 

The AVMA (American Veterinary Medical Association), which represents 80,000 Veterinarians around the nation, understandably keeps track of these cases.

 

They also maintain several  FAQs on H1N1 and pets.

 

» Veterinarians 2009 H1N1 FAQs

» Pet owners 2009 H1N1 FAQs

» General 2009 H1N1 FAQs

» Pandemic preparedness for veterinarians

 

 

Over the past year or so, we’ve seen ample evidence of non-human infection by the novel H1N1 virus (e.g.  turkeys, swine, ferrets, dogs, cats . . . even a cheetah).

 

This influenza’s propensity to cross species has also been observed with the H5N1 bird flu virus as well.

 

A few past blogs on the unusually promiscuous nature of the swine H1N1 influenza strain include:

 

US: Dog Tests Positive For H1N1

US: Turkey Farm Reports H1N1

Study: H1N1 And Birds

Cat Got Your Virus?

 

Cats seem to be more severely affected than dogs, at least based on the limited number of cases detected. Of eleven known feline cases, only 4 have recovered.

 

Last October we saw a study (see  EID Journal: Pandemic H1N1 Infection In Cats) that looked at the pathogenesis of novel H1N1 in domestic felines.

 

Experimental Pandemic (H1N1) 2009 Virus Infection of Cats

DOI: 10.3201/eid1611.100845
van den Brand JMA, Stittelaar KJ, van Amerongen G, van de Bildt M, Leijten LL, Kuiken T, et al. Experimental pandemic (H1N1) 2009 virus infection of cats. Emerg Infect Dis. 2010 Nov; [Epub ahead of print]

Conclusions

Intratracheal infection of domestic cats with pandemic (H1N1) 2009 virus resulted in mild-to-moderate clinical signs and virus replication throughout the respiratory tract that caused diffuse alveolar damage.

 

Pathogenic changes in the respiratory tract in cats were similar to those that occur in humans, macaques, and ferrets (7,11–13). Seroconversion of sentinel cats indicated cat-to-cat transmission.

 

The full study runs about 4 pages, with heavy emphasis on the necropsy and histological examination of these laboratory cats several days post infection.

 

Those discomforted by such details might want to skip the full paper.

 

While usually producing less dramatic symptoms, cats infected with the pandemic H1N1 virus showed similar pathogenic processes to cats infected with the HPAI H5N1 bird flu virus.

 

None of this is to suggest that your pet presents a serious H1N1 infection risk to you or your family.  Quite the opposite, in fact.

 

Your pet is far more likely to contract the virus from  you or other members of your household.

 

But promiscuous flu viruses - those capable of expanding their host range to other species - are a bit more worrisome because they have more opportunities to mutate, reassort, or evolve.

 

So we watch for signs of species jumping of any influenza with considerable interest.

»» Read More

Study: Dogs And H5N1

 

 

# 4699

 

 

A study that I saw a couple of days ago posted by Ironorehopper on his website was re-tweeted this morning by @Dutchy123 and posted on FluTrackers. 

 

It looks at the susceptibility of dogs to the H5N1 `bird flu’ virus, and it seems like good fodder for a blog on this long 4th of July weekend.

 

First the abstract from PubMed.gov, then some background.

 

Virology. 2010 Jun 25. [Epub ahead of print]

 

Dogs are highly susceptible to H5N1 avian influenza virus.

Chen Y, Zhong G, Wang G, Deng G, Li Y, Shi J, Zhang Z, Guan Y, Jiang Y, Bu Z, Kawaoka Y, Chen H.

Animal Influenza Laboratory of the Ministry of Agriculture and National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Harbin 150001, People's Republic of China.

Abstract

Replication of avian influenza viruses (AIVs) in dogs may facilitate their adaptation in humans; however, the data to date on H5N1 influenza virus infection in dogs are conflicting.

To elucidate the susceptibility of dogs to this pathogen, we infected two groups of 6 beagles with 10(6) 50% egg-infectious dose of H5N1 AIV A/bar-headed goose/Qinghai/3/05 (BHG/QH/3/05) intranasally (i.n.) and intratracheally (i.t.), respectively.

The dogs showed disease symptoms, including anorexia, fever, conjunctivitis, labored breathing and cough, and one i.t. inoculated animal died on day 4 post-infection. Virus shedding was detected from all 6 animals inoculated i.n. and one inoculated i.t.

Virus replication was detected in all animals that were euthanized on day 3 or day 5 post-infection and in the animal that died on day 4 post-infection. Our results demonstrate that dogs are highly susceptible to H5N1 AIV and may serve as an intermediate host to transfer this virus to humans. Copyright © 2010 Elsevier Inc. All rights reserved.

PMID: 20580396 [PubMed - as supplied by publisher]

 

 

Although there’s not been much in the way of direct research done with dogs and avian flu, over the years we’ve seen several reports that suggest that dogs are susceptible to the virus.

 

 

Dogs are not normally considered vulnerable to influenza viruses, although in recent years an equine H3N8 influenza has jumped species  to canines and has spread across the country (see the CDC’s  Key Facts about Canine Influenza (Dog Flu)).

 

 

However, last December we saw a report of a dog from the Katonah Bedford Veterinary Center in Bedford Hills, New York, tested positive for the pandemic H1N1 virus (US: Dog Tests Positive For H1N1).

 

Prior to that, we saw reports out of China where two dogs had been infected with the H1N1 virus as well (see China Reports 2 Dogs With H1N1).

 

So, while probably not very common, dogs can apparently contract the new H1N1 virus.

 

Regarding the more virulent H5N1 `bird flu’ virus, we have reports as well, including this 2006 Dispatch to the CDC’s EID Journal.

 

 

Dispatch

Volume 12, Number 11–November 2006

Fatal Avian Influenza A H5N1 in a Dog

Thaweesak Songserm,* Alongkorn Amonsin,† Rungroj Jam-on,* Namdee Sae-Heng,* Nuananong Pariyothorn,† Sunchai Payungporn,† Apiradee Theamboonlers,† Salin Chutinimitkul,† Roongroje

Abstract
Avian influenza H5N1 virus is known to cross the species barrier and infect humans and felines.

We report a fatal H5N1 infection in a dog following ingestion of an H5N1-infected duck during an outbreak in Thailand in 2004. With new reports of H5N1 virus continuing across Asia, Europe, and Africa, this finding highlights the need for monitoring of domestic animals during outbreaks.

The following year, in:

Avian Influenza (H5N1) Susceptibility and Receptors in Dogs 

(Maas R, Tacken M, Ruuls L, Koch G, van Rooij E, Stockhofe-Zurwieden N. Avian influenza (H5N1) susceptibility and receptors in dogs. Emerg Infect Dis. 2007 Aug; [Epub ahead of print]),

Researchers  determined that dogs have susceptible receptor cells in their upper and lower respiratory tracts, and can shed the virus while not manifesting clinical symptoms of the disease.

 

Their conclusion was:

 

Our results demonstrate that dogs are susceptible to infection with avian influenza (H5N1) virus and can shed virus from the nose without showing apparent signs of disease.

Moreover, receptors for avian (H5N1) virus are present not only in the lower part of the respiratory tract of dogs but also in their trachea and nose, which are potential portals of entry for the virus.

 

Different viruses have an affinity for different types of cells.  That is why most viruses are selective as to what organ systems they attack, or even what species are susceptible.

 

This explains why a virus might affect a dog, or a cat, or a bird, yet not affect humans.  This species selectivity is known as a `host range'.

 

Most viruses generally have a fairly narrow host range (there are exceptions, of course.  Like rabies).

 

The receptor binding domain (RBD) of the H5N1 virus is that area of its genetic sequence that allows it to attach to, and infect, host cells.    Much like a key into a padlock, the RBD must `fit' the host cell in order for it to bind.

 

The H5N1 virus has shown an ability to infect a surprisingly wide range of hosts.  

 

Many species of birds are susceptible, of course.  But we've also seen infections in cats (including tigers), dogs,  martens, civets, and of course humans.

 

Researchers have successfully infected cattle with the H5N1 virus, along with ferrets and mice.

 

When it comes to infecting hosts, the H5N1 virus isn't apparently very particular.

 

Which may help explain the persistence of the virus in endemic areas, even after eradication and culling of avian hosts has taken place.

»» Read More

US: Dog Tests Positive For H1N1

 

 

# 4181

 

 

In November, we began hearing reports of dogs in China that had tested positive for the novel H1N1 virus.  The first hint came from a CTV newscast (see China Worries Over Species Jumping H1N1) that I blogged about on November 11th.

 

On November 28th, we received more confirmation (see China Reports 2 Dogs With H1N1) with this news report from Xinhua News.

 

China urges intensified supervision on A/H1N1 flu in animals

www.chinaview.cn  2009-11-28 09:43:42

BEIJING, Nov. 28 (Xinhua) -- China's Ministry of Agriculture has called for intensified monitoring and investigation of A/H1N1 flu in animals after two samples from sick dogs were tested positive for the virus.

 

The veterinary clinic of College of Veterinary Medicine at the China Agricultural University reported Wednesday that two out of 52 samples from sick dogs were tested positive for A/H1N1 flu virus, the ministry said late Friday.

 

While conventional wisdom has been that dogs and cats are not normally susceptible to `human-adapted’ influenza, if you blog about influenza long enough – you stop being surprised when the `rules’ are bent.

 

Cats, after all, we were not thought likely to be susceptible to the novel H1N1 virus  either . . .  until, that is, reports of infected cats began to come in a little over two months ago.

 

Followers of the avian influenza story, of course, know that dogs and cats have both been infected by the H5N1 virus.

 

Dr. C.A. Nidom demonstrated in 2006 that of 500 cats he tested in and around Jakarta, 20% had antibodies for the bird flu virus.   For an overview of a number of other cases, see Apparently They Didn't Get The Memo.

 

We’ve not heard of dogs being infected by the H1N1 virus before, although there have been reports of dogs being infected by the H5N1 avian flu.   See also Study: Dogs Can Shed H5N1 Virus.

 

Of course, H5N1 is avian flu, with different receptor binding domains than human flu.   

 

While it probably happens more often than we know, yesterday the first confirmation of canine infection with the novel H1N1 here in the United States was released by Idexx labs.

 

Here are excerpts from the IDEXX Labs press release

 

INDUSTRY ALERT from IDEXX Reference Laboratories:H1N1 influenza virus infection confirmed in household pets

A dog from the Katonah Bedford Veterinary Center in Bedford Hills, New York, has tested positive for the H1N1 virus on the IDEXX H1N1 Influenza Virus RealPCR™ Test.

 

A 13-year-old dog had a several-day history of not feeling or eating well, a dry cough and a fever on presentation to its veterinarian. The dog was treated for pneumonia and improved with hospitalization and supportive care. The dog tested positive on the IDEXX H1N1 Influenza Virus RealPCR Test. A more detailed case description is available.

Background

In the United States, the H1N1 influenza virus has been confirmed recently as the cause of respiratory disease in several ferrets and cats resulting in more than one death in each of these species. These infections were believed to have been contracted from infected owners. There was an unconfirmed report of dogs infected in China in late November. The case described here is what is believed to be the first reported case of a dog infected with the H1N1 influenza virus in the United States. The dog’s owner had also recently tested positive for H1N1 influenza virus. The Iowa State University Veterinary Diagnostic Laboratory has confirmed independently that the influenza strain is the new pandemic strain circulating in the human population and not a swine-specific H1N1 strain.

(Continue . . . )

 

 

The concern here isn’t so much that dogs or cats will give the virus to humans.  Transmission from pet to owner has not yet been established (although it is certainly possible).  

 

Right now, there are plenty of opportunities to contract the illness from humans, without worrying about getting it from a pet.

 

It is far more likely that a pet will catch this virus from their owner, than the other way around.

 

Apart from the scientific curiosity as to why novel H1N1 should have a wider host range (swine, turkeys, felines, canines, ferrets, etc.) than most influenza viruses, the real concern is over the possibility that H1N1’s promiscuous behavior could lead to the creation of mutated or reassorted strains of the virus.

 

 

Of course, this same mutation could occur in swine, birds, humans, or practically any other host the virus can infect.  

 

So we shouldn’t stigmatize our pets as potential incubators of a mutated virus.  It could just as easily happen in a turkey, a pig, or even your next door neighbor.

 

There is also a theory that states that the more susceptible hosts a virus can find, the less evolutionary pressure it will have to mutate.  

 

If true, the ability of this virus to infect more hosts could be seen as good news.  Of course, it’s just a theory . . .   

 

All of which means we have a lot more to learn about this virus in particularly, and influenza viruses in general, before we can begin to predict how all of this turns out.

 

Stay Tuned.

»» Read More

China Reports 2 Dogs With H1N1

 

 

# 4091

 

A little over 2-weeks ago we saw a video report from CCTV (China Central Television) news that voiced concerns over the H1N1 virus species jumping to pigs, cats, and according to that report . . . even dogs (see China Worries Over Species Jumping H1N1).

 

Dogs are not normally thought of as able to contract `human flu’ – although if you blog about influenza long enough, you learn not to discount something simply because its never been seen before . . .

 

Cats, after all, we were not thought likely to be susceptible to the novel H1N1 virus  either . . .  until, that is, reports of infected cats began to come in a little over a month ago.

 

Followers of the avian influenza story, of course, know that dogs and cats have both been infected by the H5N1 virus.  

 

Dr. C.A. Nidom demonstrated in 2006 that of 500 cats he tested in and around Jakarta, 20% had antibodies for the bird flu virus.   For an overview of a number of other cases, see Apparently They Didn't Get The Memo.

 

We’ve not heard of dogs being infected by the H1N1 virus before, although there have been reports of dogs being infected by the H5N1 avian flu.   See also Study: Dogs Can Shed H5N1 Virus.

 

Of course, H5N1 is avian flu, with different receptor binding domains than human flu. 

 

Six months ago, many scientists would probably have opined that dogs could not catch this `human flu’.  With the recent discovery of the virus in cats, some veterinarians and scientists have modified that stance to it being `unlikely’ that dogs would be susceptible.

 

Those with a more cautious bent, however, have simply have stated that there’s been `no evidence of human-to-dog transmission of the H1N1 virus’.

 

Well . . . not until now, anyway.

 

Today, at least according to Chinese state run media, we’ve what appears to be confirmation of reports of dogs infected with the novel H1N1 virus, with this story (hat tip Treyfish on FluTrackers) from Xinhua news.

 

Which proves . . . when it comes to influenza, one is wise to never say never.

 

 

 

China urges intensified supervision on A/H1N1 flu in animals

 

www.chinaview.cn  2009-11-28 09:43:42

BEIJING, Nov. 28 (Xinhua) -- China's Ministry of Agriculture has called for intensified monitoring and investigation of A/H1N1 flu in animals after two samples from sick dogs were tested positive for the virus.

 

The veterinary clinic of College of Veterinary Medicine at the China Agricultural University reported Wednesday that two out of 52 samples from sick dogs were tested positive for A/H1N1 flu virus, the ministry said late Friday.

 

Analysis of genetic composition found the virus detected in the samples and those found on human A/H1N1 flu cases were 99 percent homologous, it said.

 

The ministry urged local authorities to further enhance prevention and control, intensify monitoring and investigation in animal cases of A/H1N1 flu and closely watch the virus mutation situation in animals.

»» Read More